A suspected US missile strike by a drone aircraft flattened a militant hideout in north-western Pakistan today, killing 27 local and foreign insurgents, intelligence officials said.

Several more purported militants were wounded in the attack in South Waziristan, a militant stronghold near the Afghan border. The victims apparently included about 15 ethnic Uzbek militants and several Afghans.

Two of the officials said dozens of followers of Pakistan's top Taliban leader, Baitullah Mehsud, were staying in the housing compound in the village of Shrawangai Nazarkhel when it was hit.

Pakistan's former government and the CIA have named Mehsud as the prime suspect in planning the December 2007 killing of the former prime minister Benazir Bhutto near Islamabad. Pakistani officials accuse him of harbouring foreign fighters, some linked to al-Qaida, and of training suicide bombers.

The US embassy had no comment on today's incident, while Pakistani government and army spokespeople were unavailable.

The new US administration has brushed off Pakistani criticism that missile strikes fuel religious extremism and anti-American sentiment. Pilotless US aircraft are believed to have launched more than 30 attacks since July, and American officials say al-Qaida's leadership has been decimated. Pakistani officials say the vast majority of the victims are civilians.

Pakistani leaders told the visiting American envoy, Richard Holbrooke, earlier this week that missile strikes undermined the government's own counterinsurgency strategy. Analysts suspect that Pakistan has tacitly consented to the attacks in order not to endanger billions of dollars in American and western support for its military and ailing economy.

Pakistan's pro-western government, led by Bhutto's widower, Asif Ali Zardari, has signed peace deals with tribal leaders in the north-west while launching a series of military operations against hardliners. Government forces are bogged down in several regions and Taliban militants have sustained a campaign that has included a string of kidnappings and other attacks on foreigners.

On Friday, a group holding an American employee of the United Nations warned it would kill him within 72 hours, and issued a grainy video of the blindfolded captive saying he was "sick and in trouble". Gunmen seized John Solecki on 2 February after shooting dead his driver as they drove to work in Quetta, near the Afghan border.

The kidnappers identified themselves as the Baluchistan Liberation United Front, suggesting a link to local separatists rather than the Taliban or al-Qaida. They are demanding the release of hundreds of people allegedly held in Pakistan. Officials said the group was unknown and had yet to contact the United Nations.

This week a video was released showing Taliban militants apparently beheading an abducted Polish geologist. If confirmed, the Pole's slaying would be the first killing of a western hostage in Pakistan since the American journalist Daniel Pearl was killed in 2002.

Zardari said in an interview with CBS television to air tomorrow that the Taliban had expanded their presence to a "huge amount" of Pakistan.

He sought to counter the view of many Pakistanis that the country was fighting Islamist militants only at Washington's behest, saying: "We're fighting for the survival of Pakistan. We're not fighting for the survival of anybody else."